1. Field of the Invention
This invention relates to the art of pressure shaft seals in particular to a method for sealing and a method for reducing bond breakage and increasing reliability in pressure shaft seals.
2. Description of the Prior Art
A common mode of failure of pressure seals is bond breakage at the pierce or hole cut in the radial flange of the reinforcing metal case or shell bonded to the elastomeric sealing member.
It is an object of the present invention to greatly reduce the possibility of bond breakage at the pierce and to therefore improve the reliability of pressure shaft seals and to provide improved pressure sealing methods whereby seals can operate under greater pressures with slight modification and expense.
It is a further object of the present invention to provide a shaft seal and a method for reducing bond breakage in pressure shaft seals by providing an offset on the axially outer surface of the radial flange at the radially inner end thereof to prevent rubber flow during molding from wiping the bonding cement off of the pierce or endwall of the radial flange and to provide the pierce or endwall of the radial flange as a non-cylindrical radius or taper facing axially inwardly to reduce the shear pressure exerted on the bond at the endwall.